There have been proposed endovascular devices which can be deployed into the vasculature, particularly in the region of the aortic bifurcation, so that an aneurysm in the aorta can be bridged by placement of the endovascular device with a proximal portion which seals into a non-aneurysed portion of the aorta adjacent to the renal arteries, a first leg which extends down one iliac artery to a non-aneurysed portion of the iliac artery and another short leg into which a leg extension may be placed to extend into a non-aneurysed portion of the contra-lateral iliac artery.
There can be problems, however, if the aneurysm of the aorta extends down into one or other of the iliac arteries. Each of the common iliac arteries branches into the internal and external iliac arteries and it is necessary in such a situation that a blood flow path can be directed through an endovascular stent graft into each of these arteries. In particular, it is desirable to introduce a leg extension onto the internal iliac artery from a bifurcation in the endovascular device. Access to the internal iliac artery for a medical device introducer through an already placed stent graft can be difficult from the contralateral iliac artery and hence there has been proposed, such as in US Patent Publication No. 20070250154, the use of a valve to facilitate access to the internal iliac artery. An introducer for the leg extension can be placed through the valve and after introduction of the leg extension the introducer can be withdrawn and the valve can then close to prevent blood loss from the endovascular device into the aneurysed region.
The object of this invention is to provide an endovascularly deployed medical device with a valve arrangement which can assist in solving this problem or at least provide a physician with a useful alternative.
Throughout this specification the term distal with respect to a portion of the aorta, a deployment device or a prosthesis means the end of the aorta, deployment device or prosthesis further away in the direction of blood flow away from the heart and the term proximal means the portion of the aorta, deployment device or end of the prosthesis nearer to the heart. When applied to other vessels, similar terms such as caudal and cranial should be understood.